1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * RTC subsystem, nvmem interface
 4 *
 5 * Copyright (C) 2017 Alexandre Belloni
 
 
 
 
 6 */
 7
 8#include <linux/err.h>
 9#include <linux/types.h>
10#include <linux/nvmem-consumer.h>
11#include <linux/rtc.h>
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
12
13int devm_rtc_nvmem_register(struct rtc_device *rtc,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
14		       struct nvmem_config *nvmem_config)
15{
16	struct device *dev = rtc->dev.parent;
17	struct nvmem_device *nvmem;
18
19	if (!nvmem_config)
20		return -ENODEV;
21
22	nvmem_config->dev = dev;
23	nvmem_config->owner = rtc->owner;
24	nvmem = devm_nvmem_register(dev, nvmem_config);
25	if (IS_ERR(nvmem))
26		dev_err(dev, "failed to register nvmem device for RTC\n");
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
27
28	return PTR_ERR_OR_ZERO(nvmem);
29}
30EXPORT_SYMBOL_GPL(devm_rtc_nvmem_register);

 
  1/*
  2 * RTC subsystem, nvmem interface
  3 *
  4 * Copyright (C) 2017 Alexandre Belloni
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License version 2 as
  8 * published by the Free Software Foundation.
  9 */
 10
 11#include <linux/err.h>
 12#include <linux/types.h>
 13#include <linux/nvmem-consumer.h>
 14#include <linux/rtc.h>
 15#include <linux/sysfs.h>
 16
 17/*
 18 * Deprecated ABI compatibility, this should be removed at some point
 19 */
 20
 21static const char nvram_warning[] = "Deprecated ABI, please use nvmem";
 22
 23static ssize_t
 24rtc_nvram_read(struct file *filp, struct kobject *kobj,
 25	       struct bin_attribute *attr,
 26	       char *buf, loff_t off, size_t count)
 27{
 28	struct rtc_device *rtc = attr->private;
 29
 30	dev_warn_once(kobj_to_dev(kobj), nvram_warning);
 31
 32	return nvmem_device_read(rtc->nvmem, off, count, buf);
 33}
 34
 35static ssize_t
 36rtc_nvram_write(struct file *filp, struct kobject *kobj,
 37		struct bin_attribute *attr,
 38		char *buf, loff_t off, size_t count)
 39{
 40	struct rtc_device *rtc = attr->private;
 41
 42	dev_warn_once(kobj_to_dev(kobj), nvram_warning);
 43
 44	return nvmem_device_write(rtc->nvmem, off, count, buf);
 45}
 46
 47static int rtc_nvram_register(struct rtc_device *rtc, size_t size)
 48{
 49	int err;
 50
 51	rtc->nvram = devm_kzalloc(rtc->dev.parent,
 52				sizeof(struct bin_attribute),
 53				GFP_KERNEL);
 54	if (!rtc->nvram)
 55		return -ENOMEM;
 56
 57	rtc->nvram->attr.name = "nvram";
 58	rtc->nvram->attr.mode = 0644;
 59	rtc->nvram->private = rtc;
 60
 61	sysfs_bin_attr_init(rtc->nvram);
 62
 63	rtc->nvram->read = rtc_nvram_read;
 64	rtc->nvram->write = rtc_nvram_write;
 65	rtc->nvram->size = size;
 66
 67	err = sysfs_create_bin_file(&rtc->dev.parent->kobj,
 68				    rtc->nvram);
 69	if (err) {
 70		devm_kfree(rtc->dev.parent, rtc->nvram);
 71		rtc->nvram = NULL;
 72	}
 73
 74	return err;
 75}
 76
 77static void rtc_nvram_unregister(struct rtc_device *rtc)
 78{
 79	sysfs_remove_bin_file(&rtc->dev.parent->kobj, rtc->nvram);
 80}
 81
 82/*
 83 * New ABI, uses nvmem
 84 */
 85int rtc_nvmem_register(struct rtc_device *rtc,
 86		       struct nvmem_config *nvmem_config)
 87{
 88	if (!IS_ERR_OR_NULL(rtc->nvmem))
 89		return -EBUSY;
 90
 91	if (!nvmem_config)
 92		return -ENODEV;
 93
 94	nvmem_config->dev = rtc->dev.parent;
 95	nvmem_config->owner = rtc->owner;
 96	rtc->nvmem = nvmem_register(nvmem_config);
 97	if (IS_ERR_OR_NULL(rtc->nvmem))
 98		return PTR_ERR(rtc->nvmem);
 99
100	/* Register the old ABI */
101	if (rtc->nvram_old_abi)
102		rtc_nvram_register(rtc, nvmem_config->size);
103
104	return 0;
105}
106EXPORT_SYMBOL_GPL(rtc_nvmem_register);
107
108void rtc_nvmem_unregister(struct rtc_device *rtc)
109{
110	if (IS_ERR_OR_NULL(rtc->nvmem))
111		return;
112
113	/* unregister the old ABI */
114	if (rtc->nvram)
115		rtc_nvram_unregister(rtc);
116
117	nvmem_unregister(rtc->nvmem);
118}